1. Technical Field
The disclosure relates to light emitting diodes, and particularly to a group III-nitride based semiconductor LED.
2. Description of the Related Art
Light emitting diodes (LEDs) have many advantages, such as high luminosity, low operational voltage, low power consumption, compatibility with integrated circuits, easy driving, long term reliability, and environmental friendliness. These advantages have promoted the wide use of LEDs as a light source. Now, LEDs are commonly applied in environmental lighting.
Electrons and holes are recombined in the active region. A lattice mismatch between the semiconductor layer (i.e., n-GaN layer) and the active layer (InGaN/AlGaN MQW layer) must be considered. Such lattice mismatch reduces recombination rate of electrons and holes reduces. That limits quantum efficiency of the LEDs and reduces the luminescence of LEDs.
Therefore, it is desirable to provide a group III-nitride based semiconductor LED which can overcome the described limitations.